Study on shock absorption performance and damage of a new staggered story isolated system

The new staggered story isolated system is developed according to the base isolated system and the mid-story isolated system. Non-linear finite element model of an eighteen stories new staggered story isolated structure is established. For a comparative analysis, the models of a base isolated structure, a mid-story isolated structure, and an aseismic structure are also established, and their shock absorption performances and damages are analyzed for comparison. The results indicate that the new staggered story isolated structure has a small seismic response, good shock absorption performance which is feasible for application. Besides, the shock absorption performance of the new staggered story isolated structure is a little worse than the base isolated structure but slightly better than the mid-story isolated structure. The bottom of core tube and the story below the frame isolated story have large acceleration response which needs to be paid more attention in design.

Impact Analysis and Structural Optimization of Crash Barriers

The primary thought of this review is to assess the impact absorbance, strength and durability properties using non-linear finite element simulations of analytical model of crash barriers. Before manufacturing and erection of crash barriers on site are generally simulated for impact performance using finite element analysis various parameters are checked such as 1) Crash performance 2) Vehicle trajectory after collision 3) Safety of the vehicular occupant.

Enhancing the Accuracy of Linear Finite Element Models of Vehicle Structures Considering Spot-Welded Flanges

Structural engineering simulations have required increasingly complex computational models to replace physical tests accurately. This work focuses on the numerical analysis of vehicle body structures, whose size and complexity make the use of very accurate nonlinear models unfeasible due to the prohibitive computational costs involved. The purpose of this study is to find a new approach to model spot-welded joints in linear finite element models of thin-wall vehicle body structures, improving the accuracy of the model without increasing its complexity. Using a set of simplified nonlinear models, we fitted the stiffness and damping properties of these welded joints and used those adjusted values into a linear model of the entire vehicle body structure. The results were compared with experimental tests, showing a clear improvement in the accuracy of the modal and frequency responses provided by the linear finite element model, but keeping its initial complexity level. The adjusted model was then used in an optimization analysis to reduce the structure's weight, leading to interesting cost savings and important reductions in the use of natural resources and carbon emissions.

An Investigation of Uniaxial Mechanical Properties of Excised Sheep Heart Muscle Fibre – Fitting of Different Hyperelastic Constitutive Models

: This paper presents the investigation of biomechanical behaviour of sheep heart fibre using uniaxial tests in various samples. Non-linear Finite Element models (FEA) that are utilised in understanding mechanisms of different diseases may not be developed without the accurate material properties. This paper presents uniaxial mechanical testing data of the sheep heart fibre. The mechanical uniaxial data of the heart fibre was then used in fitting four constitutive models including the Fung model, Polynomial (Anisotropic), Holzapfel (2005) model, Holzapfel (2000) model and the Four-fibre Family model. Even though the constitutive models for soft tissues including heart myocardium have been presented over several decades, there is still a need for accurate material parameters from reliable hyperelastic constitutive models. Therefore, the aim of this research paper is to select five hyperelastic constitutive models and fit experimental data in the uniaxial experimental data of the sheep heart fibre. A fitting algorithm was made used to optimally fitting and determination of the material parameters based on selected hyperelastic constitutive model. In this study, the evaluation index (EI) was used to measure the performance and capability of each selected anisotropic hyperelatic model. It was observed that the best predictive capability of the mechanical behaviour of sheep heart fibre the Polynomial (anisotropic) model has the EI of 100 and this means that it is the best performance when compared to all the other models.

Magnetostatic reciprocity for MR magnet design

Electromagnetic reciprocity has long been a staple in magnetic resonance (MR) radio-frequency development, offering geometrical insights and a figure of merit for various resonator designs. In a similar manner, we use magnetostatic reciprocity to compute manufacturable solutions of complex magnet geometries, by establishing a quantitative metric for the placement and subsequent orientation of discrete pieces of permanent magnetic material. Based on magnetostatic theory and non-linear finite element modelling (FEM) simulations, it is shown how assembled permanent magnet setups perform in the embodiment of a variety of designs and how magnetostatic reciprocity is leveraged in the presence of difficulties associated with self-interactions, to fulfil various design objectives, including self-assembled micro-magnets, adjustable magnetic arrays, and an unbounded magnetic field intensity in a small volume, despite realistic saturation field strengths.